The Protective Effects Of Cyclophilin A On Injury Of PC12 Cells Induced By Aβ_25-35

IntroductionAlzheimer's disease (AD) is a progressive neurodegenerative disorder, which is characterized by memory loss, confusion, and a variety of cognitive disabilities.There was found neuofibrillary tangle and senile plaque from pathology.β-amyloid has been proved to play a vital role in AD and be capable of inducing cell apoptosis presented by characteristic changes . With Aβ_25-35 induces the PC12 cell to injury establishes the AD cell model is the ideal model of the AD research in vitro.The massive experiments had proven cyclophilin A (CyPA) may protect the neuron to resist the damage which the oxidative stress creates. Boulos and so on have demonstrated that adenoviralmediated over-expression of CyPA in rat cortical neuronal cultures can protect neurons from oxidative stress and in vitro ischemia and Administration of purified CyPA protein to neuronal cultures protects neurons from oxidative stress and in vitro ischemia.The present study aimed to observe the protective effects of on CyPA injury of PC12 cells induced byβ-amyloid peptide (Aβ_25-35).Materials and MethodsCultured PC12 cells were divided into normal control group, Aβgroup (treated by Aβ_25-35) and rhCyPA group ( added with rhCyPA 30min before treated by Aβ_25-35). 1. MTT method was used to detect cell viability.The primary culture medium in 96-well culture plate was replaced by fresh culture medium containing MTT 15μl,then moculated for 4 hours,100μl DMSO was added to terminate the reaction.Automatic micro-titre board reading meter was used to detect the absorbency at 570nm(OD value),and cell viability was expressed by thr percentage of sample OD value and control OD value. 2.The morphological change of PC12 was observed by HE staining. 3.The expression of bcl-2/bax was assayed by immunohistochemical stain. The PC12 cell slides were subjected to ethanol fixation.Using SABC immunohistochemistry kit to observe bcl-2 and bax expression. Metamorph software was used to analyze the absorbency (OD value).The expression of bcl-2/bax was expressed by the absorbency (OD value). 4.The apoptosis of PC12 cells was detected by flow cytometry.PC12 cells in 25 ml culture bottle were harvested. Apoptosis rate was detected by FCM with PI staining.Date were analyzed by the first author with SPSS 12.0 software,and expressed as Mean±SD.t-test was used to compared the differences between the two groups.Results1. Cell survival rate: Cell survival rate was found declined in PC12 cells induced byβ-amyloid 23-35.OD value was significantly higher in CyPA group than those in Aβgroup.CyPA significantly increased cell survival rate.2. Morphological observation showed cell number was more and less injured cells in CyPA group than those in Aβgroup.3. Compared with control group,the expression of bcl-2 was decreased and bax was increased in Aβgroup. Compared with Aβgroup, the expression of bcl-2 was increased and bax was decreased in CyPA group.4. The number of apoptosis cell significantly increased in Aβgroup. The number of apoptosis cell in CyPA group reduced greatly compared with that of Aβgroup.ConclusionCyPA could play the protective role in PC12 cells injury induced by Aβ_25-35. CyPA treatment regulated the expressions of bcl-2 protein and bax protein of PC12 cell.